LED security light and LED security light control device thereof

ABSTRACT

A two-level LED security light includes a power supply unit, a motion sensor unit, a time setting unit, a loading and power control unit, an external control unit, and a lighting-emitting unit. The LED security light is turned on at dusk for generating a first level illumination and turned off at dawn. When the motion sensor detects any intrusion, the LED security light is switched from the first level illumination to a second level illumination for a short duration time to scare away the intruder. After the short duration time, the LED security light returns to the first level illumination for saving energy. The light emitting unit includes one or a plurality of LEDs. The time setting unit is for managing illumination timing. The external control unit is for setting illumination characteristics of the first level illumination or the second level illumination of the light emitting unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of Non-provisional application Ser.No. 14/487,334 filed on Sep. 16, 2014, which is now U.S. Pat. No.9,326,362. The U.S. Pat. No. 9,326,362 is a continuation-in-part of U.S.Pat. No. 8,866,392 filed on Aug. 31, 2011.

BACKGROUND

1. Technical Field

The present disclosure relates to a lighting apparatus, in particular,to a two-level security LED light with motion sensor

2. Description of Related Art

Lighting sources such as the fluorescent lamps, the incandescent lamps,the halogen lamps, and the light-emitting diodes (LED) are commonlyfound in lighting apparatuses for illumination purpose. Photoresistorsare often utilized in outdoor lighting applications for automaticilluminations, known as the Photo-Control (PC) mode. Timers may be usedin the PC mode for turning off the illumination or for switching to alower level illumination of a lighting source after the lighting sourcehaving delivered a high level illumination for a predetermined duration,referred as the Power-Saving (PS) mode. Motion sensors are often used inthe lighting apparatus for delivering full-power illumination thereoffor a short duration when a human motion is detected, then switchingback to the PS mode. Illumination operation controls such asauto-illumination in accordance to the background brightness detection,illumination using timer, illumination operation control using motionsensing results (e.g., dark or low luminous power to fully illuminated),and brightness control are often implemented by complex circuitries. Inparticular, the design and construction of LED drivers are still of acomplex technology with high fabrication cost.

Therefore, how to develop a simple and effective design method onillumination controls such as enhancing contrast in illumination andcolor temperature for various types lighting sources, especially thecontrols for LEDs are the topics of the present disclosure.

SUMMARY

An exemplary embodiment of the present disclosure provides a two-levelLED security light with motion sensor which may switch to a second levelillumination in the Power-Saving (PS) mode for a predetermined durationtime when a human motion is detected thereby achieve warning purposeusing method of electric current or lighting load adjustment.Furthermore, prior to the detection of an intrusion, the LED securitylight may be constantly in a first level illumination to save energy.

An exemplary embodiment of the present disclosure provides a two-levelLED security light, comprising a light emitting unit, a loading andpower control unit, a photo sensor unit, a motion sensor unit, a powersupply unit, and an external control unit coupled with the loading andpower control unit. The light emitting unit comprises at least one LED,or the light emitting unit is a LED lamp. The loading and power controlunit comprises a microcontroller electrically coupled with asemiconductor switching device, wherein the semiconductor switchingdevice is electrically connected in series with the power supply unitand the light emitting unit, wherein the microcontroller with programcodes outputs a pulse width modulation (PWM) signal to a gate electrodeof the semiconductor switching device to control the conduction periodT_(on) and the cut-off period T_(off) of the semiconductor switchingdevice for delivering different average electric currents from the powersupply unit to drive the light emitting unit for generating differentilluminations, wherein the microcontroller controls the semiconductorswitching device respectively to have a first T_(on) and a second T_(on)of the conduction period such that the light emitting unit respectivelygenerates a first level and a second level illumination characterized bylight intensity and/or color temperature according to the receivedsignal outputted from the photo sensor unit and the motion sensor unit,wherein the external control unit is for setting illuminationcharacteristics of at least one of the first level illumination and thesecond level illumination of the light emitting unit.

Another exemplary embodiment of the present disclosure provides atwo-level security light control device applicable to AC lightingsources, comprising a power supply unit, a photo sensor unit, a motionsensor unit, a loading and power control unit, a zero-crossing detectioncircuit, a phase controller, and an external control unit coupled withthe loading and power control unit. The phase controller is in-seriesconnected to an AC lighting source and an AC power source, wherein theloading and power control unit comprises a microcontroller for writingoperation program to control a conduction period of the phase controllerthereby to adjust the average power of the AC lighting source, whereinwhen an ambient light detected by the photo sensor unit is lower than apredetermined value, the AC lighting source is turned on by the loadingand power control unit thereby to generate a first level illuminationand when the ambient light detected by the photo sensor unit is higherthan the predetermined value, the AC lighting source is turned off bythe loading and power control unit; when an intrusion is detected by themotion sensor unit, the loading and power control unit changes theaverage power of the AC lighting source and a second level illuminationis generated for a predetermined duration, wherein the first level andthe second level illumination are characterized by specific lightintensity and/or color temperature, wherein the external control unit isfor setting illumination characteristics of at least one of the firstlevel illumination and the second level illumination of the lightemitting unit.

Another one exemplary embodiment of the present disclosure provides atwo-level security light control device applicable to AC lightingsources, comprising a power supply unit, a photo sensor unit, a motionsensor unit, a loading and power control unit, a zero-crossing detectioncircuit, a plurality of phase controllers, and an external control unitcoupled with the loading and power control unit. The plurality of phasecontrollers are respectively series-connected to a plurality ofalternating current (AC) lighting sources, wherein the pairs of phasecontroller-AC lighting source are parallel-connected to an AC powersource, wherein the loading and power control unit comprises amicrocontroller for writing operation program to respectively controlconduction periods of the phase controllers thereby to respectivelyadjust the average powers of the AC lighting sources, wherein when anambient light detected by the photo sensor unit is lower than apredetermined value, the AC lighting sources are turned on by theloading and power control unit to generate a first level illuminationfor a predetermined duration and when the ambient light detected by thephoto sensor unit is higher than the predetermined value, the AClighting sources are turned off, wherein when an intrusion is detectedby the motion sensor unit, the loading and power control unit changesthe average power of the AC lighting sources to generate a second levelillumination for a predetermined duration, wherein the first level andthe second level illumination are characterized by specific lightintensity and color temperature, wherein the external control unit isfor setting the illumination characteristics of at least one of thefirst level illumination and the second level illumination of the AClighting sources.

To sum up, a two-level LED security light with motion sensor provided byan exemplary embodiment in the present disclosure, may executePhoto-Control (PC) and Power-Saving (PS) modes. The PC mode may generatea second level (high level, for example) illumination for apredetermined duration then automatically switch to the PS mode by acontrol unit to generate a first level (low level, for example)illumination. When the motion sensor detects a human motion, thedisclosed LED security light may immediate switch to the second levelillumination for a short predetermined duration thereby achieveillumination or warning effect. After the short predetermined duration,the LED security light may automatically return to the first levelillumination for saving energy. Further, the illuminationcharacteristics of at least one of the first level illumination and thesecond level illumination of the light emitting unit can be set by theuser by means of an external control unit.

In order to further understand the techniques, means and effects of thepresent disclosure, the following detailed descriptions and appendeddrawings are hereby referred, such that, through which, the purposes,features and aspects of the present disclosure can be thoroughly andconcretely appreciated; however, the appended drawings are merelyprovided for reference and illustration, without any intention to beused for limiting the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure, and are incorporated in andconstitute a part of this specification. The drawings illustrateexemplary embodiments of the present disclosure and, together with thedescription, serve to explain the principles of the present disclosure.

FIG. 1 schematically illustrates a block diagram of a two-level LEDsecurity light in accordance with an exemplary embodiment of the presentdisclosure.

FIG. 2A illustrates a schematic diagram of a two-level LED securitylight in accordance to the first exemplary embodiment of the presentdisclosure.

FIG. 2B graphically illustrates a timing waveform of a pulse widthmodulation (PWM) signal in accordance to the first exemplary embodimentof the present disclosure.

FIG. 2C illustrates in some detail a schematic diagram of a two-levelLED security light of FIG. 2A.

FIG. 2D illustrates a flow chart of a free running setting method inaccordance to the first exemplary embodiment of the present disclosure.

FIG. 3A illustrates a schematic diagram of a two-level LED securitylight in accordance to the second exemplary embodiment of the presentdisclosure.

FIG. 3B illustrates a timing waveform of two-level LED security light inaccordance to the second exemplary embodiment of the present disclosure.

FIG. 4 illustrates a schematic diagram of a two-level LED security lightin accordance to the second exemplary embodiment of the presentdisclosure.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Reference is made in detail to the exemplary embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or alike parts.

(First Exemplary Embodiment)

Refer to FIG. 1, which schematically illustrates a block diagram of atwo-level LED security light in accordance to the first exemplaryembodiment of the present disclosure. A two-level LED security light(herein as the lighting apparatus) 100 includes a power supply unit 110,a photo sensor unit 120, a motion sensor unit 130, a loading and powercontrol unit 140, a light emitting unit 150, a time setting unit 160 andan external control unit 170. The power supply unit 110 is used forsupplying power required to operate the system, wherein the associatedstructure includes the known AC/DC power converter. The external controlunit 170 is coupled with the loading and power control unit 140, whereinthe external control unit 170 can be manipulated by the user foradjusting illumination characteristics of at least one of a first levelillumination and a second level illumination of the light emitting unit150. The first level and the second level illumination are characterizedby light intensity and/or color temperature. For example, the firstlevel illumination and the second level illumination may be a low levelillumination (or no illumination) and a high level illuminationrespectively, but the present disclosure is not so restricted. In otherembodiment, the first level illumination may be a first colortemperature level illumination, and the second level illumination may bea second color temperature level illumination. The photo sensor unit 120may be a photoresistor, which may be coupled to the loading and powercontrol unit 140 for determining daytime or nighttime in accordance tothe ambient light. The motion sensor unit 130 may be a passive infraredray sensor (PIR) or microwave motion sensor, which is coupled to theloading and power control unit 140 and is used to detect intrusions.When a person is entering a predetermined detection zone of the motionsensor unit 130, a sensing signal thereof may be transmitted to theloading and power control unit 140.

The loading and power control unit 140 which is coupled to the lightemitting unit 150 may be implemented by a microcontroller. The loadingand power control unit 140 may control the illumination levels of thelight emitting unit 150 in accordance to the sensing signal outputted bythe photo sensor unit 120 and the motion sensor unit 130. The lightemitting unit 150 may include a plurality of LEDs and switchingcomponents. The loading and power control unit 140 may control the lightemitting unit 150 to generate at least two levels of illuminationvariations.

When the photo sensor unit 120 detects that the ambient light is lowerthan a predetermined value (i.e., nighttime), the loading and powercontrol unit 140 executes the Photo-Control (PC) mode by turning on thelight emitting unit 150 to generate a high level illumination for apredetermined duration then return to a low level illumination forPower-Saving (PS) mode. When the photo sensor unit 120 detects that theambient light is higher than a predetermined value (i.e., dawn), theloading and power control unit 140 turns off the light emitting unit150. In the PS mode, when the motion sensor unit 130 detects a humanmotion, the loading and power control unit 140 may increase the electriccurrent which flows through the light emitting unit 150, to generate ahigh level illumination for a short predetermined duration. After theshort predetermined duration, the loading and power control unit 140 mayautomatically reduce the electric current that flows through the lightemitting unit 150 thus to have the light emitting unit 150 return to lowlevel illumination for saving energy.

Refer to FIG. 2A in view of FIG. 1, FIG. 2A illustrates a schematicdiagram of a two-level LED security light in accordance to the firstexemplary embodiment of the present disclosure. The photo sensor unit120 may be implemented by a photo sensor 220; the motion sensor unit 130may be implemented by a motion sensor 230; the loading and power controlunit 140 may be implemented by a microcontroller 240; the time settingunit 260 is the time setting unit 160; and the external control unit 270is the external control unit 170. The light emitting unit 250 includesthree series-connected LEDs L1˜L3. The LEDs L1˜L3 is connected between aDC source and a transistor Q1, wherein an artisan of ordinary skill inthe art will appreciate how to replace the transistor Q1 by other typeof the semiconductor switching device. The DC source may be provided bythe power supply unit 110. The transistor Q1 may be an N-channelmetal-oxide-semiconductor field effect transistor (NMOS). The transistorQ1 is connected between the three series-connected LEDs L1˜L3 and aground GND. The loading and power control unit 140 implemented by themicrocontroller 240 may output a pulse width modulation (PWM) signal tothe gate of transistor Q1 to control the average electric current. It isworth to note that the electric components depicted in FIG. 2A onlyserves as an illustration for the exemplary embodiment of the presentdisclose and hence the present disclosure is not limited thereto. Theexternal control unit 270 may be an electronic switch being optionally apush button, a touch panel or an infrared ray sensor for inputtingvoltage signal to adjust illumination characteristics of at least one ofthe first level illumination and the second level illumination of thelight emitting unit. Further, in another embodiment, the externalcontrol unit 270 may be a push button, a touch panel, an infrared raysensor or a wireless remote control device coupled or wirelessly linkedto a pin of the microcontroller of the loading and power control unit;wherein, when the push button, the touch panel, the infrared ray sensoror the remote control device is activated, a voltage signal is generatedto trigger the microcontroller 240 for performing at least one of thetwo functional modes, for instance the manual setting and thefree-running setting (which would be explained thereafter) of theillumination characteristics. The external control unit 270 may beelectrically coupled to the microcontroller 240 (that is the loading andpower control unit 140), such as utilizing electrically connectionthrough conducting wire. In other embodiment, the external control unit270 may be a remote control device, thus the external control unit 270is wirelessly linked to the microcontroller 240 by using wirelesstechniques.

In addition, the microcontroller 240 is coupled to a time setting unit260, wherein the time setting unit 260 may allow the user to configureon software base a virtual timer embedded in the microcontroller 240 forexecuting a subroutine for a predetermined duration to perform the firstlevel or the second level illumination respectively in the PC mode or inthe PS mode. Further, if the microcontroller 240 is coupled to a clockdevice, the time setting unit 260 may allow the user to set a clock timepoint instead of a predetermined duration for switching from the PC modeto the PS mode. However, the present disclosure is not limited thereto.

Refer to FIG. 2B concurrently, which graphically illustrates a timingwaveform of a pulse width modulation (PWM) signal in accordance to thefirst exemplary embodiment of the present disclosure. In the PC mode,the PWM signal may be used to configure the transistor Q1 to have theconduction period T_(on) being longer than the cut-off period T_(off).On the other hand in the PS mode, the PWM signal may configure thetransistor Q1 to have the conduction period T_(on) being shorter thanthe cut-off period T_(off). In comparison of the illumination levelsbetween the PC and PS modes, as the conduction period T_(on) oftransistor Q1 being longer under the PC mode, therefore have higheraverage electric current driving the light emitting unit 250 therebygenerate high illumination, which may be classified as the high levelillumination; whereas as the conduction period T_(on) of transistor Q1is shorter in the PS mode, therefore have lower average electric currentdriving the light emitting unit 250 thereby generate low illumination,which may be classified as the low level illumination.

The microcontroller 240 turns off the light emitting unit 250 during theday and activates the PC mode at night by turning on the light emittingunit 250 to generate the high level illumination for a shortpredetermined duration then return to the low level illumination therebyentering the PS mode. When the motion sensor 230 detects a human motionin the PS mode, the light emitting unit 250 may switch to the high levelillumination for illumination or warning application. The light emittingunit 250 may return to the low level illumination after maintaining atthe high level illumination for a short predetermined duration to saveenergy.

Please refer to FIG. 2A to further elucidate illumination leveladjustment or setting. In order to adjust the illumination level of thelight emitting unit 250, two exemplary control methods are applied byutilizing the external control unit 270. Specifically, the firstexemplary method is a manual adjustment applicable when the loading andpower control unit 240 executes the Power-Saving (PS) mode forgenerating a first level illumination. The first level illumination ispreferred an illumination of low light intensity and/or low colortemperature. Refer to FIG. 2A again, the microcontroller 240 may scanwith its program codes a pin connected with the external control unit270 and may detect control signal generated from the external controlunit 270. The external control unit 270 may be preferable a push button.When the push button is pressed down by a user to ground the connectingpin of the microcontroller 270, a zero voltage is generated for a timeduration until the push button is released, such that a control signalwith a zero voltage of a time duration is generated manually by theuser. The microcontroller 240 with program codes recognizes this controlsignal and by executing a subroutine generates a PWM signal with aconduction time period T_(on) periodically varying within a preset rangeof 0 to 50% duty (T_(on) is equal to T_(off)) for a time lengthcontrolled by the external control unit 270, such that the LEDs 250generate illumination with light intensity level gradually andperiodically increasing from zero to 50% of the maximum light intensityand then decreasing from 50% to zero to complete a repetitive cycle. Thetime length of such periodical illumination variation is equal to thetime duration of zero voltage generated by pushing down the push button270. Only when the push button 270 is released by the user, theperiodical illumination variation is ended at a illumination levelrelated to a specific T_(on) value determined by the user; then themicrocontroller 240 jumps out of the subroutine of periodicalillumination variation and stores thereafter the corresponding T_(on)value of the PWM signal in its memory to update a data base forgenerating a new first level illumination in the PS mode. In brief, bypressing down and releasing the push button 270 connected with a pin ofthe microcontroller 240, the illumination level of the light emittingunit 250 can be thus set manually by the user when the loading and powercontrol unit 240 executes the PS mode. However, the present disclosureis not limited thereto.

The second exemplary method is a free-running setting by program codesof microcontroller in conjunction with the external control unit. Referto FIG. 2A. When the lighting apparatus is turned on by the photo sensor220, the microcontroller 240 starts its program codes by executing asubroutine in which PWM signal is generated with the conduction timeperiod T_(on) periodically varying within a preset range of 0 to 50%duty for a fixed time period, such that the LEDs 250 generateillumination with light intensity level gradually and periodicallyincreasing from zero to 50% of the maximum light intensity and thendecreasing from 50% to zero light intensity to complete a variationcycle. This periodical variation of the low illumination level can lastfreely for two or three cycles within the fixed time period which ispreferable to be one minute. However, it is not to limit the presentinvention in this manner. Within the one-minute fixed time period, forinstance, the periodical illumination variation may be ended byactivating the external control unit 270. The external control unit 270may be preferable a push button. When the push button is pressed downinstantly by a user to ground the connecting pin of the microcontroller270, a zero voltage is generated to trigger the microcontroller 240wherein the microcontroller 240 jumps out of the subroutine to terminatethe free-running illumination variation and stores the T_(on) value ofPWM signal corresponding to the time point when the external controlunit 270 being activated. The stored T_(on) value is used to update adata base for generating the first level illumination in the PS mode.The free-run of periodical illumination variation may automatically endwhen the one-minute fixed time period expires with the external controlunit 270 not being operated by the user; in this case, themicrocontroller 240 jumps out of the subroutine of free-run and acquiresfrom its memory a preset or earlier T_(on) value of PWM signal forgenerating the first level illumination in the PS mode until thelighting apparatus is turned off.

In brief, in a preferred embodiment of the present disclosure, atwo-level LED security light may include a power supply unit, a photosensor unit, a motion sensor unit, a loading and power control unit, alight emitting unit, a time setting unit and an external control unit.The external control unit is provided for adjusting or settingillumination level of LED light. The loading and power control unit isimplemented by a microcontroller with program codes to operate thetwo-level LED security light. The microcontroller turns off the lightemitting unit during the day and activates a Power-Saving (PS) mode atnight by turning on the light emitting unit to generate a first levelillumination, and upon human motion detection by switching the lightemitting unit to generate a second level illumination for a short timeduration. The illumination characteristics of first level illuminationcan be changed by activating the external control unit according to theuser's demand. When the lighting apparatus is turned on, themicrocontroller starts its program codes by firstly executing asubroutine with free-run for a fixed time length, such that the user canfollow the gradual and periodical illumination variation to select anillumination level by operating the external control unit; thereafter,the microcontroller jumps out of the subroutine of free-run and executesthe program codes of PS mode for generating the first level illuminationwith the selected level characteristics until the lighting apparatus isturned off. If within the fixed time length of free-run the externalcontrol unit is not activated, the microcontroller jumps out of thesubroutine of free-run automatically and, with a data base of a presetor earlier level characteristics, executes program codes of PS mode forgenerating the first level illumination until the lighting apparatus isturned off. The level characteristics can also be further adjustedmanually by the user when loading and power control unit executes the PSmode. The external control unit may be preferable a push button. When inPS mode the light emitting unit generates a first level illumination,the user can press the push button for a while to observe the gradualand periodical changing of level characteristic, and then decide at atime point to release the push button to select a desired illuminationlevel, such that to complete manual adjustment.

Please refer to FIG. 2C in view of FIG. 2A and FIG. 2B. Two preferredconstructions respectively for the time setting unit 260′ and theexternal control unit 270′ are shown in FIG. 2C. The time setting unit260′ may be a voltage divider with variable resistor for settingpredetermined time durations for the first level and the second levelillumination. The external control unit 270′ may include a voltagedivider 270 a which may comprise a variable resistor provided with arotating knob to facilitate operation. For illumination level setting,the microcontroller operates with program codes preferably inconjunction with the voltage divider 270 a and further with a powersupply detection circuit 270 b, an energy storage capacitor 270 c and apower switch (not shown in FIG. 2C) for respectively manual andfree-running setting of at least one of a first level illumination and asecond level illumination of the two-level LED security light; detailsof adjusting illumination level with the external control unit 270′ andother extra devices will be described later.

In order to adjust the illumination level of the light emitting unit250, two exemplary control methods are applied by utilizing the externalcontrol unit 270 a and the software technique incorporating with extradevices 270 b-270 c. Specifically, the first exemplary method is amanual adjustment applicable in the Power-Saving (PS) mode forgenerating a first level illumination. Refer to FIG. 2C again, themicrocontroller 240 may scan with its program codes the voltage on a pinconnected with the voltage divider 270 a and may detect a voltage, inwhich the voltage across of the variable resistor (voltage divider 270a) may be varied manually when a user rotates the knob attached on thevariable resistor (voltage divider 270 a). The microcontroller 240 withprogram codes generates in response a PWM signal with a conduction timeperiod T_(on) proportional to a voltage received from the variableresistor (voltage divider 270 a). The light emitting unit 250illuminates accordingly with light intensity level characterized by theconduction time period T_(on) controlled by the voltage of the variableresistor (voltage divider 270 a). With the external control unit 270′,the first illumination level of the light emitting unit 250 can be thusset manually by tuning the variable resistor (voltage divider 270 a)when the loading and power control unit 240 executes the PS mode.

The second exemplary method is a free-running adjustment based onprogram codes of microcontroller in conjunction with a power supplydetection circuit and an energy-stored capacitor. Refer to FIG. 2C, whenthe lighting apparatus is turned on, the microcontroller 240 starts itsprogram codes firstly by executing a subroutine of free-run in which PWMsignal is generated with the conduction time period T_(on) periodicallyvarying within a preset range of 0 to 50% duty for a fixed time period,such that the LEDs 250 generate illumination with light intensity levelgradually and periodically increasing from zero to 50% of the maximumlight intensity and then decreasing from 50% to zero to complete avariation cycle. This periodical variation of the low illumination levelcan last freely for two or three cycles within the fixed time periodwhich is preferable to be one minute. However, it is not to limit thepresent invention in this manner. Within the one-minute fixed timeperiod, for instance, the free-run of periodical illumination variationmay be overridden by the user by turning off a power switch momentarily(for 1-2 seconds) and then switching it back on. At the moment when thepower switch is turned off and then switched back on, themicrocontroller 240 detects this OFF-ON event through a power supplydetection circuit 270 b and leaves the subroutine to terminate free-run,and simultaneously stores the T_(on) value of PWM signal related to thetime point of the OFF-ON event to update a data base for generating thefirst level illumination in the PS mode. In general, the user can followthe gradual and periodical free-run of the low level lighting variationand select a favorable light intensity level by promptly turning thepower switch off and again on (short power interruption). Afteroverriding by power interruption, the microcontroller 240 jumps out ofthe subroutine of free-run and continues its program codes to executethe PS mode in which the illumination level is determined by the user.The free-run of periodical lighting variation may end automatically whenthe fixed time period expires with power interruption not beingdetected; the microcontroller 240 jumps out of the subroutine offree-run and acquires from its memory a preset or earlier T_(on) valueof PWM signal for generating the first level illumination in the PSmode. Refer to FIG. 2C again, an energy storage capacitor 270 c isconnected between the high end and the ground of the working voltageV_(DD). This capacitor 270 c is for holding the voltage V_(DD) to keepthe circuits 240, 270 b still working when electric power is interruptedfor 1-2 seconds. Therefore, when overriding free-run by short powerinterruption, an instant zero voltage is detected by the power supplydetection circuit 270 b and recognized by the microcontroller 240 toperform function for selecting and setting a desired illumination level.

In another embodiment, refer to FIG. 1 again, when an ambient lightdetected by the photo sensor unit 120 is lower than a predeterminedvalue, the light emitting unit 150 may be turned on thereby by theloading and power control unit 140 to generate an adjustable levelillumination for a first predetermined duration and then turned off orswitched to a low level illumination, when an intrusion is detected bythe motion sensor unit 130, the light emitting unit 150 is turned on bythe loading and power control unit 140 to generate a high levelillumination for a second predetermined duration and then turned off orswitched to a low level illumination until the next intrusion detection;when an ambient light detected by the photo sensor unit 120 is higherthan the predetermined value, the light emitting unit 150 is turned offby the loading and power control unit. The time setting unit 160 is usedto set the first and the second predetermined duration respectively forthe adjustable level illumination and the high level illumination. Theexternal control unit 170 is used in two setting modes for settingillumination characteristics of the adjustable level illumination;wherein the first setting mode is a manual setting, in which theillumination level of the light emitting unit is set in a preset rangeby activating the external control unit; 170 wherein the second settingmode is a free-running setting, in which the light emitting unitperforms a free-run of the adjustable level illumination with lightintensity gradually and periodically increasing and then decreasing in apreset range to complete a cycle, wherein the free-run may be terminatedby activation of the external control unit 170 at a time pointcorresponding to a specific light intensity level, such that the lightemitting unit performs the adjustable level illumination constantly withthe specific light intensity level being set thereof.

In still another embodiment, a lighting management device is provided.Refer to FIG. 1 again, the lighting management device applicable to alighting load such as the light emitting unit 150. The lightingmanagement device comprises the loading and power control unit 140, thepower supply unit 110 and the external control unit 170 coupled with theloading and power control unit. The loading and power control unit 140comprises a microcontroller (such as the microcontroller 240 shown inFIG. 2A) electrically coupled with a semiconductor switching device(such as the transistor Q1 shown in FIG. 2A). The external control unit170 may be a push button, a touch panel, an infrared ray sensor or aremote control device coupled or wirelessly linked to a pin of themicrocontroller. The semiconductor switching device is electricallyconnected in series with the power supply unit and the lighting load,such as the transistor Q1 is electrically connected in series with theDC source and the light emitting unit 250, wherein the microcontrollerwith written program code controls the conduction rate of thesemiconductor switching device, wherein the external control unit 170enables a user to select a desired illumination characteristic during afree running setting process performed by the lighting load, wherein thelighting load operates a free-run of illumination level by gradually andperiodically changing the illumination characteristic, wherein thefree-run may be terminated by activation of the external control unit170 at a time point corresponding to a specific illuminationcharacteristic selected by the user, wherein the microcontrolleraccordingly interprets the conduction rate of the semiconductorswitching device at the time point when the external control unit 170 isactivated and the free running is terminated to be the illuminationcharacteristic set for illumination performance, the illuminationcharacteristic is then memorized by the microcontroller for repetitiveperformance. Further, in one embodiment, the free run setting isterminated and the illumination characteristic of the lighting load isset by turning off a power switch instantly and turning it back on atthe time point the lighting load performs a desired lightingcharacteristic selected by the user.

According to the previous embodiment, a free running setting method withactivation of external control unit or through power switch interruptionis provided. Refer to FIG. 2D, the method comprises step S110: selectinga desired illumination characteristic during a free running settingprocess performed by the lighting load by an the external control unit;S120: utilizing the lighting load to operate a free-run of illuminationlevel by gradually and periodically changing the illuminationcharacteristic; and S130: terminating the free-run by activating of theexternal control unit or through power switch interruption at a timepoint corresponding to a specific illumination characteristic selectedby the user, wherein the microcontroller accordingly interprets theconduction rate of the semiconductor switching device at the time pointwhen the external control unit is activated or a power switchinterruption is detected and the free running is terminated to be theillumination characteristic set for illumination performance, theillumination characteristic is then memorized by the microcontroller forrepetitive performance.

In summary, in a preferred embodiment of the present disclosure, atwo-level LED security light may employ an external control unit coupledto a loading and power control unit for adjusting or setting theillumination level of the LED light. The external control unit may be apush button, a voltage divider, a touch panel, an infrared ray sensor orother devices for generating control signals having different attributesdepending on the category of the external control unit. For instance, apush button generates a binary signal having a zero voltage lasting fora time length equal to the time duration while the push button beingpushed down; quite different, a voltage divider generates a DC voltagetuned by rotating a rotary knob attached to the voltage divider. Theloading and power control unit may be implemented by a microcontrollerwith program codes designed respectively accommodating to differentcontrol signals of different attributes for generating PWM signal withT_(on) value variable according to the control signal attribute, such asto carry out illumination level adjustment or setting. The illuminationlevel characteristics including light intensity and color temperaturecan be thus set by operating the external control unit.

(Second Exemplary Embodiment)

Refer back to FIG. 1, wherein the light emitting unit 150 may include aphase controller and one or more parallel-connected alternating current(AC) LEDs. The phase controller is coupled between the described one ormore parallel-connected ACLEDs and AC power source. The loading andpower controller 140 in the instant exemplary embodiment may through thephase controller adjust the average power of the light emitting unit 150so as to generate variations in the first level and the second levelilluminations. Refer to FIG. 3A and FIG. 4 in conjunction with FIG. 1,this embodiment provides a two-level security light control deviceapplicable to AC lighting sources, comprising the power supply unit 110,the photo sensor unit 120 (that is the photo sensor 220), the motionsensor unit 130 (that is the motion sensor 230), the loading and powercontrol unit 140 (that is the microcontroller 240), a zero-crossingdetection circuit 453, a plurality of phase controllers (one phasecontroller 452 shown in FIG. 3A and one phase controllers 551 shown inFIG. 4 are exemplary illustrated), the time setting unit 160 (that isthe variable 260′) and the external control unit 270′ coupled with theloading and power control unit 240.

Refer to FIG. 3A, which illustrates a schematic diagram of a two-levelLED security light 100 in accordance to the second exemplary embodimentof the present disclosure. The operation of the external control 270′can be referred to FIG. 2C and the related description of manual andfree-running setting of illumination level, and the earlier descriptionthus the redundant information is not repeated. It is worth mentioningthat the power supply detection circuit 270 b is implemented by thezero-crossing detection circuit 453, and the power switch mentioned inthe previous embodiment can be implemented by the power switch 160 aelectrically coupled to the AC power source and the zero-crossingdetection circuit 453. For a two-level LED security light setting up atthe ceiling or a high site far from the user, the free-run setting ofthe illumination level through instant power interruption by utilizingthe power switch 160 a is very convenient for the user, in which no anyadded switching device is needed. The main difference between FIG. 3Aand FIG. 2C is in that the light-source load is an ACLED, which iscoupled to the AC power source, and further the light emitting unit 450includes a phase controller 451, for ease of explanation, but thepresent disclosure is not so restricted. The phase controller 451 isin-series connected to the AC lighting source (ACLED) and the AC powersource, wherein the microcontroller 240 is for writing operation programto control a conduction period of the phase controller 451 thereby toadjust the average power of the AC lighting source (ACLED). In anotherembodiment, a plurality of phase controller 451 can be also controlledby the microcontroller 240. The phase controller 451 includes abi-directional switching device 452, here, a triac, a zero-crossingdetection circuit 453, and a resistor R. The microcontroller 240 turnsoff the light emitting unit 450 when the photo sensor 220 detects thatthe ambient light is higher than a predetermined value. Conversely, whenthe photo sensor 220 detects that the ambient light is lower than thepredetermined value, the microcontroller 240 activates the PC mode byturning on the light emitting unit 450. In the PC mode, themicrocontroller 240 may select a control pin for outputting a pulsesignal which through a resistor R triggers the triac 452 to have a largeconduction angle. The large conduction angle configures the lightemitting unit 450 to generate a high level illumination for apredetermined duration. Then the microcontroller 240 outputs the pulsesignal for PS mode through the same control pin to trigger the triac 452to have a small conduction angle for switching the light emitting unit450 from the high level illumination to the low level illumination ofthe PS mode. Moreover, when the motion sensor 230 (also called motionsensor unit) detects a human motion in the PS mode, the microcontroller240 temporarily outputs the PC-mode pulse signal through the samecontrol pin to have the light emitting unit 450 generated the high levelillumination for a short predetermined duration. After the shortpredetermined duration, the light emitting unit 450 returns to the lowlevel illumination.

In the illumination control of the ACLED, the microcontroller 240 mayutilize the detected zero-crossing time (e.g., the zero-crossing time ofan AC voltage waveform) outputted from the zero-crossing detectioncircuit 453 to send an AC synchronized pulse signal thereof which maytrigger the triac 452 of the phase controller 451 thereby to change theaverage power input to the light emitting unit 450. As the ACLED has acut-in voltage V_(t) for start conducting, thus if the pulse signalinaccurately in time triggers the conduction of the triac 452, then theinstantaneous value of AC voltage may be lower than the cut-in voltageV_(t) of ACLED at the trigger pulse. Consequently, the ACLED may resultin the phenomenon of either flashing or not turning on. Therefore, thepulse signal generated by the microcontroller 240 must fall in a propertime gap behind the zero-crossing point associated with the ACsinusoidal voltage waveform.

Supposing an AC power source having a voltage amplitude V_(m) andfrequency f, then the zero-crossing time gap t_(D) of the trigger pulseoutputted by the microcontroller 240 should be limited according tot_(o)<t_(D)<½f−t_(o) for a light-source load with a cut-in voltageV_(t), wherein t_(o)=(½πf) sin⁻¹(V_(t)/V_(m)). The described criterionis applicable to all types of ACLEDs to assure that the triac 452 can bestably triggered in both positive and negative half cycle of the ACpower source. Take ACLED with V_(t) (rms)=80V as an example, andsupposing the V_(m) (rms)=110V and f=60 Hz, then t_(o)=2.2 ms and(½f)=8.3 ms may be obtained. Consequently, the proper zero-crossing timegap t_(D) associated with the phase modulation pulse outputted by themicrocontroller 240 which lagged the AC sinusoidal voltage waveformshould be designed in the range of 2.2 ms<t_(D)<6.1 ms.

Refer to FIG. 3B, which illustrates a timing waveform of the two-levelLED security light in accordance to the second exemplary embodiment ofthe present disclosure. Waveforms (a)˜(d) of FIG. 3B respectivelyrepresent the AC power source, the output of the zero-crossing detectioncircuit 453, the zero-crossing delay pulse at the control pin of themicrocontroller 240, and the voltage waveform across the two ends of theACLED in the light emitting unit 450. The zero-crossing detectioncircuit 453 converts the AC voltage sinusoidal waveform associated withthe AC power source to a symmetric square waveform having a low and ahigh voltage levels as shown in FIG. 3B(b). At the zero-crossing pointof the AC voltage sinusoidal wave, the symmetric square waveform maytransit either from the low voltage level to the high voltage level orfrom the high voltage level to the low voltage level. Or equivalently,the edge of the symmetric square waveform in the time domain correspondsto the zero-crossing point of the AC voltage sinusoidal waveform. Asshown in FIG. 3B(c), the microcontroller 240 outputs a zero-crossingdelay pulse in correspondence to the zero-crossing point of the ACsinusoidal waveform in accordance to the output waveform of thezero-crossing detection circuit 453. The zero-crossing delay pulse isrelative to an edge of symmetric square waveform behind a time gap t_(D)in the time domain. The t_(D) should fall in a valid range, as describedpreviously, to assure that the triac 452 can be stably triggered therebyto turn on the ACLED. FIG. 3B(d) illustrates a voltage waveform appliedacross the two ends associated with the ACLED. The illumination level ofthe light emitting unit 450 is related to the conduction period t_(on)of the ACLED, or equivalently, the length t_(on) is directlyproportional to the average power inputted to the ACLED. The differencebetween the PC mode and the PS mode being that in the PC mode, the ACLEDhas longer conduction period, thereby generates the high levelillumination; whereas in the PS mode, the ACLED conduction period isshorter, hence generates the low level illumination.

Refer to FIG. 3A and FIG. 3B concurrently for setting ACLED illuminationlevel. In manual setting, the microcontroller 240 with program codescontrols the conduction time period t_(on) of the ACLED to be in apreset range 0<t_(on)<¼f−t₀; wherein by tuning the variable resistor(voltage divider 270 a) the light intensity level of the ACLED can beadjusted between zero and 50% of the maximum light intensity. In thefree-run setting of illumination level, the microcontroller 240 withprogram codes controls the conduction time period t_(on) of the ACLED toperiodically change in a preset range 0<t_(on)<¼f−t₀, such that theACLED generates illumination gradually and periodically increasing fromzero to 50% and then decreasing from 50% to zero of the maximum lightintensity. When following the free-run of lighting variation, theillumination level can be set through power interruption momentarily byutilizing the power switch 160 a.

Refer to FIG. 4, which illustrates a schematic diagram of a two-levelLED security light 100 in accordance to the second exemplary embodimentof the present disclosure. The operation of the external control 270′can be referred to FIG. 2C and the related description of manual andfree-running setting of illumination level, and the earlier descriptionthus the redundant information is not repeated. It is worth mentioningthat the power supply detection circuit 270 b is implemented by thezero-crossing detection circuit 554, and the power switch mentioned inthe previous embodiment can be implemented by the power switch 160 aelectrically coupled to the AC power source and the zero-crossingdetection circuit 554. The light emitting unit 550 of the lightingapparatus 100 includes an ACLED1, an ACLED2, and a phase controller 551.The phase controller 551 can be treated as two phase controllers 451(shown in FIG. 3A) which are parallel-connected. In still anotherembodiment, a plurality of phase controllers (451 or 551) arerespectively series-connected to a plurality of alternating current (AC)lighting sources (ACLED), wherein the pairs of phase controller-AClighting source are parallel-connected to the AC power source. The phasecontroller 551 includes triacs 552 and 553, the zero-crossing detectioncircuit 554 as well as resistors R1 and R2. The light emitting unit 550of FIG. 4 is different from the light emitting unit 450 of FIG. 3A inthat the light emitting unit 550 has more than one ACLEDs and more thanone bi-directional switching devices. Furthermore, the colortemperatures of the ACLED1 and the ACLED2 may be selected to bedifferent.

In the exemplary embodiment of FIG. 4, the ACLED1 has a high colortemperature, and the ACLED2 has a low color temperature. In the PC mode,the microcontroller 240 uses the phase controller 551 to trigger bothACLED1 and ACLED2 to conduct for a long period, thereby to generate thesecond level illumination as well as illumination of mix colortemperature. In the PS mode, the microcontroller 240 uses the phasecontroller 551 to trigger only the ACLED2 to conduct for a short period,thereby generates the first level illumination as well as illuminationof low color temperature. Moreover, in the PS mode, when the motionsensor 230 detects a human motion, the microcontroller 240 may throughthe phase controller 551 trigger the ACLED1 and the ACLED2 to conductfor a long period. Thereby, it may render the light emitting unit 450 togenerate the second level illumination of high color temperature and toproduce high contrast in illumination and hue, for a short predeterminedduration to warn the intruder. Consequently, the lighting apparatus maygenerate the first level or the second level illumination of differenthue. The rest of operation theories associated with the light emittingunit 550 are essentially the same as the light emitting unit 450 andfurther descriptions are therefore omitted.

A lighting apparatus may be implemented by integrating a plurality ofLEDs with a microcontroller and various types of sensor components inthe controlling circuit in accordance to the above described twoexemplary embodiments. This lighting apparatus may automaticallygenerate first level illumination when the ambient light detected isinsufficient and time-switch to the low level illumination. In addition,when a person is entering the predetermined detection zone, the lightingapparatus may switch from the first level illumination to the secondlevel illumination, to provide the person with sufficient illuminationor to generate strong illumination and hue contrast for monitoring theintruder. Further, the illumination characteristic of at least one ofthe first level illumination and the second level illumination of thelight emitting unit can be set through two setting modes, namely, manualand free-running setting, such that the illumination characteristic isset to fulfill user's demand by activating an external control unit.

The above-mentioned descriptions represent merely the exemplaryembodiment of the present disclosure, without any intention to limit thescope of the present disclosure thereto. Various equivalent changes,alternations or modifications based on the claims of present disclosureare all consequently viewed as being embraced by the scope of thepresent disclosure.

What is claimed is:
 1. An LED security light, comprising: a lightemitting unit; a loading and power control unit; a photo sensor unit; amotion sensor unit; a power supply unit; and an external control unit,electrically coupled with the loading and power control unit; whereinthe light emitting unit is an LED lamp; wherein the loading and powercontrol unit comprises a microcontroller electrically coupled with acontrollable semiconductor switching device, wherein the controllablesemiconductor switching device is electrically connected in series witha power source and with the light emitting unit, wherein themicrocontroller outputs a control signal to control conduction rate ofthe controllable semiconductor switching device for delivering differentaverage electric powers to drive the light emitting unit for generatingdifferent illumination modes according to control signals received fromthe photo sensor unit and the motion sensor unit, wherein when anambient light detected by the photo sensor unit is lower than a firstpredetermined value, the motion sensor unit is switched on and the lightemitting unit is simultaneously managed by the loading and power controlunit to perform a first level illumination mode, wherein when theambient light detected by the photo sensor unit is higher than a secondpredetermined value, the light emitting unit and the motion sensor unitare turned off by the loading and power control unit, wherein when amotion intrusion is detected by the motion sensor unit, the loading andpower control unit manages to increase the average electric powerdelivered to the light emitting unit to perform a second levelillumination mode for a predetermined duration, and then the lightemitting unit is resumed to perform the first level illumination mode,wherein the first level illumination mode and the second levelillumination mode are respectively characterized with specific lightintensity, wherein the light intensity of the second level illuminationmode is always higher than the light intensity of the first levelillumination mode, wherein the external control unit is at least usablefor adjusting and setting the light intensity of at least oneillumination mode.
 2. The LED security light according to claim 1,wherein the illumination mode is the first level illumination mode,wherein the external control unit is used for adjusting and setting thelight intensity of the first level illumination mode.
 3. The LEDsecurity light according to claim 1, wherein the illumination mode isthe second level illumination mode, wherein the external control unit isused for adjusting and setting the light intensity of the second levelillumination mode.
 4. The LED security light according to claim 1,wherein the external control unit is further usable for adjusting andsetting a time length of the predetermined duration for performing thesecond level illumination mode.
 5. The LED security light according toclaim 1, wherein the external control unit comprises at least a pushbutton, a touch panel, an infrared ray sensor or a wireless remotecontrol device electrically coupled to at least a pin of themicrocontroller of the loading and power control unit; wherein when thepush button, the touch panel, the infrared ray sensor or the wirelessremote control device is operated, a voltage signal readable andinterpretable to the microcontroller is thereby generated to trigger themicrocontroller to activate a corresponding subroutine designed foradjusting and setting the light intensity of at least one of the firstlevel illumination mode or the second level illumination mode.
 6. TheLED security light according to claim 5, wherein the wireless remotecontrol device is a Wi-Fi wireless control signal receiver, a Blue Toothwireless control signal receiver or a RF (radio frequency) wirelesscontrol signal receiver.
 7. The LED security light according to claim 6,wherein the first level illumination mode can be preset at zero.
 8. TheLED security light according to claim 1, wherein the external controlunit is a push button, a touch panel, an infrared ray sensor or awireless remote control device; wherein when the push button, the touchpanel, the infrared ray sensor or the wireless remote control device isactivated, at least one of a first voltage signal with a binary formator a second voltage signal with a binary format readable andinterpretable to the microcontroller is generated to trigger themicrocontroller to activate at least one of a first subroutine or asecond subroutine, wherein the first subroutine is designed foradjusting and setting the light intensity of the first levelillumination mode or the second level illumination mode, wherein thesecond subroutine is designed for adjusting and setting a time length ofthe predetermined duration for performing the second level illuminationmode.
 9. The LED security light according to claim 8, wherein thewireless remote control device is a Wi-Fi wireless control signalreceiver, a Blue Tooth wireless control signal receiver or a RF (radiofrequency) wireless control signal receiver.
 10. The LED security lightaccording to claim 9, wherein the light intensity of the first levelillumination mode can be preset at zero.
 11. The LED security lightaccording to claim 9, wherein the microcontroller comprises a memory forsaving or installing an application program (APP) or a software program,wherein the application program (APP) from an internet or a cloud serveris downloaded for updating the memory of the microcontroller.
 12. TheLED security light according to claim 1, wherein the external controlunit comprises at least one voltage divider; wherein the voltage dividercomprises a variable resister, wherein the voltage divider iselectrically connected to a pin of the microcontroller, wherein when thevoltage divider is operated, a DC voltage is selected and generated bytuning the variable resister to trigger the microcontroller to activatea corresponding subroutine designed for adjusting and setting the lightintensity of at least one of the first level illumination mode or thesecond level illumination mode.
 13. The LED security light according toclaim 1, wherein the power supply unit is an AC/DC power converter toconvert an AC power source into DC power required for operating the LEDsecurity light, wherein the power source is a DC power from the powersupply unit; wherein the controllable semiconductor switching device isa unidirectional semiconductor switching device, wherein themicrocontroller outputs a PWM (pulse width modulation) signal to controla conduction period (T_(on)) and a cutoff period (T_(off))of thecontrollable semiconductor switching device for delivering differentaverage currents from the power supply unit to drive the light emittingunit for generating different illumination modes, wherein themicrocontroller controls the controllable semiconductor switching devicerespectively to have a short conduction period (T_(on)) and a longconduction period (T_(on)) such that the light emitting unitrespectively generated a first level illumination mode and a secondlevel illumination mode characterized by different light intensityaccording to the signals received from the photo sensor unit and themotion sensor unit.
 14. The LED security light according to claim 1,wherein the power supply unit is a battery module to output DC power foroperating the LED security light, wherein the power source is a DCpower, wherein the controllable semiconductor switching device is aunidirectional semiconductor switching device, wherein themicrocontroller outputs a PWM (pulse width modulation) signal to controla conduction period (T_(on)) and a cutoff period (T_(off)) of thecontrollable semiconductor switching device for delivering differentaverage electric currents from the power supply unit to drive the lightemitting unit for generating different illumination modes, wherein themicrocontroller controls the unidirectional semiconductor switchingdevice respectively to have a short conduction period (T_(on)) and along conduction period (T_(on)) such that the light emitting unitrespectively generate a first level illumination mode and a second levelillumination mode characterized by different light intensity accordingto signals received from the photo sensor unit and the motion sensorunit.
 15. The LED security light according to claim 14, wherein thebattery module is a solar battery module comprising a solar panelcircuitry for charging the solar battery.
 16. The LED security lightaccording to claim 1, wherein the power supply unit is an AC/DC powerconverter to convert an AC power source into DC power for operating theLED security light, wherein the power source is the AC power source,wherein the light emitting unit is a LED lamp adaptable to the AC powersource, wherein the controllable semiconductor switching device is aphase controller comprising a bidirectional semiconductor switchingdevice, wherein a zero-crossing detection circuit is electricallycoupled to the microcontroller, wherein the bidirectional semiconductorswitching device is connected in series between the AC power source andthe LED lamp, wherein the microcontroller incorporating with thezero-crossing detection circuit outputs a time delay pulse laggingbehind the zero-crossing point in each half cycle of the AC power sourceto control the conduction rate of the phase controller for deliveringdifferent average AC power to drive the LED lamp for generatingdifferent illumination modes according to control signals received fromthe photo sensor unit and the motion sensor unit.
 17. The LED securitylight according to claim 16, wherein the LED lamp is a DC LED modulebridging one port to a full wave rectifier to receive AC power deliveredby the power supply unit controlled by the loading and power controlunit.
 18. The LED security light according to claim 16, wherein the LEDlamp is an AC LED module comprising two polarity reverse LED arraysconnected in parallel, wherein the first LED array conducts a positivehalf cycle of the AC power controlled by the loading and power controlunit while the second LED array conducts a negative half cycle of the ACpower controlled by the loading and power control unit.
 19. The LEDsecurity light according to claim 16, wherein in order to ensure asuccessful conduction, the phase controller is confined to operate in adimmable phase time domain between t₀ and 1/(2f)−t₀, wherein f is thefrequency of the AC power source and t₀ is a corresponding phase time ofa cut-in voltage at which the LED lamp starts to emit light.
 20. An LEDsecurity light, comprising: a light emitting unit; a loading and powercontrol unit; a photo sensor unit; a motion sensor unit; a power supplyunit; and an external control unit, electrically coupled with theloading and power control unit; wherein the light emitting unit is anLED lamp, wherein the loading and power control unit comprises amicrocontroller, wherein the microcontroller is electrically coupled toa controllable semiconductor switching device, wherein the controllablesemiconductor switching device is electrically connected in series witha power source and with the light emitting unit, wherein themicrocontroller outputs a control signal to control conduction rate ofthe controllable semiconductor switching device for delivering differentaverage electric powers to drive the light emitting unit for generatingdifferent illumination modes according to control signals received fromthe photo sensor unit or motion sensor unit; wherein when an ambientlight detected by the photo sensor unit is lower than a firstpredetermined value, the light emitting unit is thereby turned on by theloading and power control unit to perform a first level illuminationmode for a first predetermined duration, then the light emitting unit isswitched to perform a second level illumination mode, wherein when theambient light detected by the photo sensor unit is higher than a secondpredetermined value, the light emitting unit is thereby turned off bythe loading and power control unit, wherein when a motion intrusion isdetected by the motion sensor unit, the loading and power control unitmanages to increase the average electric power delivered to the lightemitting unit to generate a high level illumination mode for a secondpredetermined duration, wherein the first level illumination mode, thesecond level illumination mode and the high level illumination mode arerespectively characterized with specific light intensity, wherein thelight intensity of the high level illumination mode is always higherthan the light intensity of the second level illumination mode; whereinthe external control unit is at least usable for adjusting and settingthe light intensity for at least one of the first level illuminationmode, the second level illumination mode or the high level illuminationmode.
 21. The LED security light according to claim 20, wherein theexternal control unit is further usable for adjusting and setting a timelength of the first predetermined duration for performing the firstlevel illumination mode.
 22. The LED security light according claim 20,wherein the external control unit is further usable for adjusting andsetting a time length of the second predetermined duration forperforming the high level illumination mode.
 23. The LED security lightaccording to claim 20, wherein the external control unit is furtherusable for alternately performing between a motion sensor controlledillumination mode and an adjustable timer controlled illumination mode,wherein when the LED security light is in the adjustable timercontrolled illumination mode, the motion sensor unit is disabledtemporarily till at the time when a time period preset by the adjustabletimer expires or till at a clock time point selected by the adjustabletimer and the motion sensor unit is then enabled; the external controlunit is further usable for adjusting and setting the light intensity ofthe adjustable timer controlled illumination mode, the external controlunit is additionally usable for adjusting and setting a time length orthe clock time point for performing the adjustable timer controlledillumination mode; wherein when the LED security light is in the motionsensor controlled illumination mode, the external control unit isfurther usable for adjusting and setting the light intensity of at leastone of the first level illumination mode, the second level illuminationmode and the high level illumination mode, the external control unit isalso usable for adjusting and setting the time length of at least one ofthe first predetermined duration for performing the first levelillumination mode or the second predetermined duration for performingthe high level illumination mode.
 24. The LED security light accordingto claim 20, wherein the external control unit is at least a pushbutton, a touch panel, an infrared ray sensor, or a wireless remotecontrol device coupled to at least one pin of the microcontroller of theloading and power control unit; wherein when the push button, the touchpanel, the infrared ray sensor or a wireless remote control device isoperated, a voltage signal readable and interpretable to themicrocontroller is thereby generated to trigger the microcontroller toactivate a first corresponding subroutine designed for adjusting andsetting the light intensity of at least one of the first levelillumination mode, the second level illumination mode or the high levelillumination mode; or the microcontroller to activate a secondcorresponding subroutine designed for adjusting and setting a timelength of at least one of the first predetermined duration forperforming the first level illumination mode or the second predeterminedduration for performing the high level illumination mode.
 25. The LEDsecurity light according to claim 24, wherein the wireless remotecontrol device is a Wi-Fi wireless control signal receiver, a Blue Toothwireless control signal receiver or a RF (radio frequency) wirelesscontrol signal receiver.
 26. The LED security light according to claim25, wherein the light intensity of the second level illumination modecan be preset at zero.
 27. The LED security light according to claim 25,wherein the microcontroller comprises a memory for saving or installingan application (APP) or a software program, wherein the applicationprogram or software program from an internet or a cloud server isdownloaded to update the memory.
 28. The LED security light according toclaim 20, wherein the external control unit comprises at least onevoltage divider, wherein the voltage divider comprises a variableresister, wherein the voltage divider is electrically connected to a pinof the microcontroller, wherein when the voltage divider is operated, aDC voltage is selected and generated by tuning the variable resister totrigger the microcontroller to activate a corresponding subroutinedesigned for adjusting and setting a time length of at least one of thefirst predetermined duration or the second predetermined duration. 29.The LED security light according to claim 28, wherein the lightintensity of the second level illumination mode can be preset at zero.30. The LED security light according to claim 20, wherein the externalcontrol unit comprises a power supply detecting circuit connectable to apower switch and at least two voltage dividers; wherein the power switchis a rocker switch connected to an AC power source to control power onand power off; wherein when instantly turning the power switch off andturning the power switch back on in a short preset time interval, theelectric power interruption is detected by the microcontroller throughthe power supply detecting circuit, the microcontroller thereby managesto switch alternately between performing a motion sensor controlledillumination mode and performing a photo sensor controlled dusk to dawnillumination mode; wherein the first voltage divider is a dimmercircuitry comprising a first variable resister, wherein the secondvoltage divider is a time setting unit comprising a second variableresister, wherein the first voltage divider is electrically connected toone pin of the microcontroller, wherein the second voltage divider iselectrically connected to another pin of the microcontroller, whereinwhen the first voltage divider is operated, a first DC voltage isselected and generated by tuning the first variable resister to triggerthe microcontroller to activate a first corresponding subroutinedesigned for setting the light intensity for at least one of the firstlevel illumination mode, the second level illumination mode and the highlevel illumination mode; wherein when the second voltage divider isoperated, a second DC voltage is selected and generated by tuning thesecond variable resister to trigger the microcontroller to activate asecond corresponding subroutine for setting a time length of at leastthe first predetermined duration for performing the first levelillumination mode or the second predetermined duration for performingthe high level illumination mode.
 31. The LED security light accordingto claim 30, wherein the light intensity of the second levelillumination mode can be preset at zero.
 32. The LED security lightaccording to claim 20, wherein the power supply unit is an AC/DC powerconverter to convert an AC power source into DC power required foroperating the LED security light, wherein the power source is an ACpower source, wherein the light emitting unit is an LED lamp adaptableto the AC power source, wherein the controllable semiconductor switchingdevice is a phase controller comprising a bidirectional semiconductorswitching device, wherein a zero-crossing detection circuit iselectrically coupled to the microcontroller, wherein the phasecontroller is connected in series between the AC power source and theLED lamp, wherein the microcontroller incorporating with thezero-crossing detection circuit outputs a time delay pulse laggingbehind the zero-crossing point in each half cycle of the AC power sourceto control the conduction rate of the phase controller for deliveringdifferent average AC power to drive the LED lamp for generatingdifferent illumination modes according to the control signals receivedfrom the photo sensor unit and the motion sensor unit.
 33. The LEDsecurity light according to claim 32, wherein the LED lamp is a DC LEDmodule bridging one port to a full wave rectifier to receive AC powerdelivered by the power supply unit controlled by the loading and powercontrol unit.
 34. The LED security light according to claim 32, whereinthe LED lamp is an AC LED module comprising two polarity reverse LEDarrays connected in parallel, wherein the first LED array conducts apositive half cycle of the AC power controlled by the loading and powercontrol unit while the second LED array conducts a negative half cycleof the AC power controlled by the loading and power control unit. 35.The LED security light according to claim 32, wherein in order to ensurea successful conduction, the phase controller is confined to operate ina dimmable phase time domain between t₀ and 1/(2f)−t₀, wherein f is thefrequency of AC power source and t₀ is a corresponding phase time of acut-in voltage at which the LED lamp starts to emitting light.
 36. TheLED security light according to claim 20, wherein the power supply unitis an AC/DC power converter to convert an AC power source into DC powerpower required for operating the LED security light, wherein the powersource is a DC power from the power supply unit; wherein thecontrollable semiconductor switching device is a unidirectionalsemiconductor switching device, wherein the microcontroller outputs aPWM (pulse width modulation) signal to control a conduction period(T_(on)) and a cutoff period (T_(off)) of the controllable semiconductorswitching device for delivering different average currents from thepower supply unit to drive the light emitting unit for generatingdifferent illumination modes characterized by different light intensityaccording to the signals received from the photo sensor unit and themotion sensor unit.
 37. The LED security light according to claim 20,wherein the power supply unit is a battery module to output DC power foroperating the LED security light, wherein the power source is a DCpower, wherein the controllable semiconductor switching device is aunidirectional semiconductor switching device, wherein themicrocontroller outputs a PWM (pulse width modulation) signal to controla conduction period (T_(on)) and a cutoff period (T_(off)) of thecontrollable semiconductor switching device for delivering differentaverage electric currents from the power supply unit to drive the lightemitting unit for generating different illumination modes characterizedby different light intensity according to signals received from thephoto sensor unit and the motion sensor unit.
 38. The LED security lightaccording to claim 37, wherein the battery module is a solar batterymodule comprising a solar panel circuitry for charging the solarbattery.
 39. An LED security light control device, comprising: a loadingand power control unit; a photo sensor unit; a power supply unit; and anexternal control unit, electrically coupled with the loading and powercontrol unit; wherein the LED security light control device isconnectable to an LED lamp, wherein the loading and power control unitcomprises a microcontroller, wherein the microcontroller is electricallycoupled to a controllable semiconductor switching device, wherein thecontrollable semiconductor switching device is electrically connectablein series with a power source and with the LED lamp, wherein themicrocontroller outputs a control signal to control conduction rate ofthe controllable semiconductor switching device for delivering differentaverage electric power to drive the LED lamp for generating differentillumination modes according to control signals received from the photosensor unit; wherein when an ambient light detected by the photo sensorunit is lower than a first predetermined value, the LED lamp is therebyturned on by the loading and power control unit to generate a firstlevel illumination mode for a first predetermined duration, then the LEDlamp is switched to a second level illumination mode, wherein when theambient light detected by the photo sensor unit is higher than a secondpredetermined value, the LED lamp is thereby turned off by the loadingand power control unit; wherein the external control unit is at leastusable for adjusting and setting a light intensity for at least thesecond level illumination mode.
 40. The LED security light controldevice according claim 39, wherein the external control unit is furtherusable for adjusting and setting a time length of at least the firstpredetermined duration for performing the first level illumination mode.41. The LED security light control device according to claim 39, whereinthe external control unit comprises at least a push button, a touchpanel, an infrared ray sensor or a wireless remote control deviceelectrically coupled to a pin of the microcontroller, wherein when thepush button, the touch panel, the infrared ray sensor or the wirelessremote control device is operated, a voltage signal readable andinterpretable to the microcontroller is thereby generated to trigger themicrocontroller to activate a corresponding subroutine; wherein thecorresponding subroutine is designed for adjusting and setting at leastthe light intensity of the second level illumination mode, or foradjusting and setting a time length of at least the first predeterminedduration for performing the first level illumination mode.
 42. The LEDsecurity light control device according to claim 41, wherein thewireless remote control device is a Wi-Fi wireless control signalreceiver, a Blue Tooth wireless control signal receiver or a RF (radiofrequency) wireless control signal receiver.
 43. The LED security lightcontrol device according to claim 42, wherein the microcontroller has amemory for saving or installing an application program (APP) or anapplication software, wherein the application program or applicationsoftware from an internet or a cloud server is downloaded to update thememory of the microcontroller.
 44. The LED security light control deviceaccording to claim 39, wherein the external control unit comprises atleast one voltage divider, wherein the voltage divider comprises avariable resister, wherein the voltage divider is electrically connectedto a pin of the microcontroller, wherein when the voltage divider isoperated, a DC voltage is selected and generated by tuning the variableresister to trigger the microcontroller to activate a subroutinedesigned for setting at least the light intensity of the second levelillumination mode or to activate a subroutine designed for adjusting andsetting at least a time length of the first predetermined duration forperforming the first level illumination mode.
 45. The LED security lightcontrol device according to claim 39, wherein the power supply unit isan AC/DC power converter to convert an AC power source into DC power foroperating the LED security light, wherein the power source is the ACpower source, wherein the light emitting unit is an LED lamp adaptableto the AC power source, wherein the controllable semiconductor switchingdevice is a phase controller comprising a bidirectional semiconductorswitching device, wherein a zero-crossing detection circuit iselectrically coupled to the microcontroller, wherein the bidirectionalsemiconductor switching device is connected in series between the ACpower source and the LED lamp, wherein the microcontroller incorporatingwith the zero-crossing detection circuit outputs a time delay pulselagging behind the zero-crossing point in each half cycle of the ACpower source to control the conduction rate of the phase controller fordelivering different average AC power to drive the LED lamp forgenerating different illumination modes according to control signalsreceived from the photo sensor unit.
 46. The LED security light controldevice according to claim 45, wherein the LED lamp is a DC LED modulebridging one port to a full wave rectifier to receive AC power deliveredby the power supply unit controlled by the loading and power controlunit.
 47. The LED security light control device according to claim 45,wherein the LED lamp is an AC LED module comprising two polarity reverseLED arrays connected in parallel, wherein the first LED array conducts apositive half cycle of the AC power controlled by the loading and powercontrol unit while the second LED array conducts a negative half cycleof the AC power controlled by the loading and power control unit. 48.The LED security light control device according to 45, wherein in orderto ensure a successful conduction, the phase controller is confined tooperate in a dimmable phase time domain between t₀ and 1/(2f)−t₀,wherein f is the frequency of the AC power source and t₀ is acorresponding phase time of a cut-in voltage at which the LED lampstarts to emit light.
 49. An LED security light control device,comprising: a loading and power control unit; a photo sensor unit; amotion sensor unit; a power supply unit; and an external control unit;wherein the LED security light control device is electricallyconnectable to an LED lamp, wherein the loading and power control unitcomprises a microcontroller, wherein the microcontroller is electricallycoupled to a controllable semiconductor switching device, wherein thecontrollable semiconductor switching device is electrically connectablein series between a power source and the LED lamp, wherein themicrocontroller outputs a control signal to control conduction rate ofthe controllable semiconductor switching device for delivering differentelectric powers to drive the LED lamp for generating differentillumination modes according to control signals received from the photosensor unit and the motion sensor unit; wherein when an ambient lightdetected by the photo sensor unit is lower than a first predeterminedvalue, the motion sensor unit is switched on and the LED lamp is managedby the loading and power control unit for performing a first levelillumination mode for a first predetermined duration, then the LED lampis switched to a second level illumination mode, wherein when theambient light detected by the photo sensor unit is higher than a secondpredetermined value, the motion sensor unit and the LED lamp are therebyswitched off by the loading and power control unit, wherein when amotion intrusion is detected by the motion sensor unit, the loading andpower control unit manages to increase the average electric powerdelivered to the LED lamp to generate a high level illumination mode fora second predetermined duration, and then the LED lamp is resumed to thesecond level illumination mode, wherein the first level illuminationmode, the second level illumination mode and the high level illuminationmode are characterized with different light intensity wherein the lightintensity of the high level illumination mode is higher than the lightintensity of the second level illumination mode; wherein the externalcontrol unit is at least usable for adjusting and setting at least thelight intensity of at least one of the first level illumination mode,the second level illumination mode and the high level illumination mode.50. The LED security light control device according to claim 49, whereinthe external control unit is further usable for adjusting and setting atleast a time length of at least the first predetermined duration forperforming the first level illumination mode or the second predeterminedduration for the high level illumination mode.
 51. The LED securitylight control device according to claim 49, wherein the external controlunit comprises at least a push button, a touch panel, an infrared raysensor or a wireless remote control device electrically coupled to atleast a pin of the microcontroller; wherein when the push button, thetouch panel, the infrared ray sensor or the wireless remote controldevice is operated, a first voltage signal readable and interpretable tothe microcontroller is selected and generated to trigger themicrocontroller to activate a first corresponding subroutine designedfor adjusting and setting at least the light intensity of at least oneof the first level illumination mode, the second level illumination modeand the high level illumination mode; wherein a second voltage signalreadable and interpretable to the microcontroller can be furtherselected and generated to activate a second corresponding subroutine foradjusting and setting a time length of at least one of the firstpredetermined duration for performing the first level illumination modeor the second predetermined duration for performing the high levelillumination mode.
 52. The LED security light control device accordingto claim 51, wherein the wireless remote control device is a Wi-Fiwireless control signal receiver, a Blue Tooth wireless control signalreceiver or a RF (radio frequency) wireless control signal receiver. 53.The LED security light control device according to claim 51, wherein thelight intensity of the second level illumination mode can be preset atzero.
 54. The LED security light control device according to claim 52,wherein the microcontroller has a memory for saving or installing anapplication program (APP) or application software, wherein theapplication program (APP) or application software from an internet orcloud server is downloaded to update the memory of the microcontroller.55. The LED security light control device according to claim 49, whereinthe external control unit comprises at least one voltage divider,wherein the voltage divider comprise a variable resister, wherein thevoltage divider is electrically connected to a pin of themicrocontroller, wherein when the voltage divider is operated, a DCvoltage is selected and generated by tuning the variable resister totrigger the microcontroller to activate a first corresponding subroutinedesigned for adjusting and setting the light intensity for at least oneof the first level illumination mode, the second level illumination modeor the high level illumination mode; or to activate a secondcorresponding subroutine designed for adjusting and setting at least atime length of the first predetermined duration for performing the firstlevel illumination mode or the second predetermined duration forperforming the high level illumination mode.
 56. The LED security lightaccording to claim 55, wherein the light intensity of the second levelillumination mode can be preset at zero.
 57. The LED security lightcontrol device according to claim 49, wherein the power supply unit isan AC/DC power converter to convert an AC power source into DC power foroperating the LED security light, wherein the power source is the ACpower source, wherein the light emitting unit is an LED lamp adaptableto the AC power source, wherein the controllable semiconductor switchingdevice is a phase controller comprising a bidirectional semiconductorswitching device, wherein a zero-crossing detection circuit iselectrically coupled to the microcontroller, wherein the bidirectionalsemiconductor switching device is connected in series between the ACpower source and the LED lamp, wherein the microcontroller incorporatingwith the zero-crossing detection circuit outputs a time delay pulselagging behind the zero-crossing point in each half cycle of the ACpower source to control the conduction rate of the phase controller fordelivering different average AC power to drive the LED lamp forgenerating different illumination modes according to control signalsreceived from the photo sensor unit and the motion sensor unit.
 58. TheLED security light control device according to claim 57, wherein the LEDlamp is a DC LED module bridging one port to a full wave rectifier toreceive AC power delivered by the power supply unit controlled by theloading and power control unit.
 59. The LED security light controldevice according to claim 57, wherein the LED lamp is an AC LED modulecomprising two polarity reverse LED arrays connected in parallel,wherein the first LED array conducts a positive half cycle of the ACpower controlled by the loading and power control unit while the secondLED array conducts a negative half cycle of the AC power controlled bythe loading and power control unit.
 60. The LED security light controldevice according to claim 57, wherein in order to ensure a successfulconduction, the phase controller is confined to operate in a dimmablephase time domain between t₀ and 1/(2f)−t₀, wherein f is the frequencyof the AC power source and t₀ is a corresponding phase time of a cut-involtage at which the LED lamp starts to emit light.
 61. The LED securitylight control device according to claim 49, wherein the power supplyunit is a battery module to output DC power to operate the LED securitylight control device, wherein the power source is DC power from thebattery module.
 62. The LED security light control device according toclaim 61, wherein the battery module is a solar battery modulecomprising a solar panel and a circuitry for charging the solar battery.